Re: [PATCH] remote_rcmd

[Andrew Cagney <ac131313@ges.redhat.com>]

> On Sun, Jul 14, 2002 at 01:48:38PM -0400, Andrew Cagney wrote:
> 
>> >
>> >Actually, the current docs suggest:
>> >
>> >-> qRcmd command
>> ><- O <HEX-OUTPUT>
>> ><- O <HEX-OUTPUT>
>> ><- <HEX-OUTPUT>
>> ><- OK
> 
>> 
>> Where?
> 
> 
>                               COMMAND (hex encoded) is passed to the
>                               local interpreter for execution.  Invalid
>                               commands should be reported using the
>                               output string.  Before the final result
>                               packet, the target may also respond with
>                               number of intermediate `O'OUTPUT console
>                               output packets.

``before the final _result_ packet''

> ...
> 
>                reply OUTPUT   A command response with the hex encoded
>                               output string OUTPUT.

This is one of several ``_result_'' packets.

>> >which confuses me.  What's supposed to differentiate the O <HEX-OUTPUT>
>> >packets from the final <HEX-OUTPUT> packet (what difference in purpose,
>> >I mean)?
> 
>> 
>> Valid replies to ``qRcmd'' are:
>> 
>> 	``OK''
>> 	``''
>> 	``<HEX-OUTPUT>''
>> 	``Enn''
>> 
>> The ``O'' packet is something separate.
> 
> 
> I think I wasn't clear in my question.  qRcmd can send some O packets,
> which are supposed to provide some ambiguous form of "output" from the
> "console", and then one <HEX-OUTPUT> packet.  What is supposed to go in
> which?  It doesn't make sense to me to limit this to one <HEX-OUTPUT>
> packet if it is arbitrary output; it may simply be too large.  On the
> other hand I'm not sure I see why both O<HEX> and <HEX> are allowed.

Sorry, you've lost me.  There are a number of choices and which is used 
is left to the implementor.  Sequences like:

	<- O output
	<- O output
	<- OK
and
	<- O output
	<- output
and
	<- output
and
	<- OK

are all valid.  To be honest, I've only seen targets use the last two. 
Typically the command response is so small that it can be safely 
squeesed into a single reply packet.

Andrew